Oil field steam generation using untreated water

Abstract

An improved method of steam generation for thermal oil recovery by delivering the produced oil-water emulsion, together with a hot hydrocarbon liquid, to a flash vessel where most of the water is flashed off as steam, which can be used for injection in further thermal oil production; while the liquid phase, containing oil, entrained solids and some water is passed to a separator, where a portion of the oil is removed as sales product, most of the water and solids are removed as waste and the remaining oil and traces of water are recirculated to a heater and a flash vessel to provide heat for further processing. If desired, the produced water-oil emulsion may first be passed through a separator vessel which divides the emulsion into three streams, hydrocarbon liquid, gas and water; with hydrocarbon liquid being sent to a coalescer vessel to produce sales quality oil, the gases sent to a fuel or flare system and the water being treated as described above.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a non-provisional of and claims benefit of U.S. provisional application 61 / 701,077, entitled “Oilfield Steam Generation Using Untreated Water,” filed Sep. 14, 2012.FIELD OF INVENTION[0002]This invention relates to thermal oil production by steam injection with the steam generated from emulsion, untreated produced water or other saline waters.BACKGROUND[0003]In traditional heavy oil recovery employing steam injection, the produced water, oil and gas flow together from the wellhead to the process factory. The produced fluids generally form an oil-water emulsion. At the process factory, the traditional process is to separate the gases and oil from the water. The oil is then treated to remove trace amounts of water and other materials to meet the required sales specification. Generally, the oil produced in thermal recovery schemes is high in density and viscosity. Therefore, a diluent, such as condensate, naphtha, light cr...

AI Technical Summary

Benefits of technology

The present invention provides an improved method for generating steam without the need for water treatment processes and equipment. This method can also remove dissolved and suspended solids from produced oil-water emulsions and recover thermal oil through steam injection. Additionally, this method can generate steam from produced water with high levels of dissolved solids.

Problems solved by technology

However, both of these prior art techniques require the steps of water separation and treatment which involve considerable expense, manpower and equipment.

Thus, none of the prior art steam generation techniques have been entirely satisfactory.

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